    [Patent Document 1] JP-B-S58-21144
Exhaust gases from an automobile engine are led from the engine into an exhaust pipe disposed on such as a chassis frame and are exhausted to the atmosphere, but this exhaust pipe is repeatedly subjected to bending stress owing to the torque reaction, inertial force, and the like of the engine. Particularly in the case of a front wheel drive (FWD) transverse engine, as compared with a longitudinal engine, this bending stress becomes quite large. Accordingly, there are risks in that the vibration of the engine can be transmitted through an exhaust pipe suspension into the vehicle compartment and cause noise, and or can cause malfunctions such as the fatigue breakage of the exhaust pipe. To overcome such problems, a means has conventionally been adopted in which an exhaust pipe joint device having a spherical pipe joint (spherical annular seal member) is disposed at a predetermined portion of the exhaust pipe to absorb the stress (JP-B-58-21144).
Such a spherical pipe joint is in many cases used in such a way that its partially convex spherical outer surface is brought into slidable contact with a partially concave spherical inner surface of a flange member secured to an end portion of a downstream-side exhaust pipe, and its cylindrical inner surface is fitted to an outer surface of a pipe end portion of an upstream-side exhaust pipe. Thus, the stress is absorbed by the relative sliding movement of the partially convex spherical outer surface with respect to the partially concave spherical inner surface of the flange member.
In the front wheel drive (FWD) transverse engine, in recent years, since the exhaust pipe (manifold) is provided on the rear side of the engine, a large force in the twisting direction (in the direction of rotation about a pipe axis of the exhaust pipe), in particular, is applied to the exhaust pipe connected to the manifold, in addition to a force in the shearing direction (in a direction perpendicular to the pipe axis direction of the exhaust pipe). This force is applied to the exhaust pipe joint device as well.
If the large force in the twisting direction is applied to the exhaust pipe joint device, stick-slip occurs between the cylindrical inner surface of the spherical pipe joint and the pipe end portion of the upstream-side exhaust pipe, which are fitted to each other, and abnormal noise attributable to the stick-slip is generated, imparting discomfort to the driver and passengers.